package chixing.day10.string;

public class String_demo2 {
    public static void main(String[] args) {
        StringBuilder builder = new StringBuilder("hello");
        builder.append("run");
        System.out.println(builder);

        String s1 = "hello";
        s1 = s1.concat("run");
        System.out.println(s1);
    }
}
